Automatic selector mechanism for radio apparatus



NOV. 13, 1951 v w LA RUE 2,574,604

AUTOMATIC SELECTOR MECHANISM FOR RADIO APPARATUS Filed NOV. 29, 1946 6 Sheets-Sheet l INVENTOR ATTORNEY W. D. LA RUE Nov. 13, 1951 AUTOMATIC SELECTOR MECHANISM FOR RADIO APPARATUS Filed Nov. 29, 1946 6 Sheets-Sheet 2 e A A.

INVENTOR Nov. 13, 1951 w. D. LA RUE I 2,574,604

' AUTOMATIC SELECTOR MECHANISM FZOR RADIO APPARATUS Filed Nov. 29, 1946 6 Sheets-Sheet 3 INVENTOR MIZZM flia film ATTORNEY Nov. 13, 1951 w. D. LA RUE 2,574,604

AUTOMATIC SELECTOR MECHANISM FOR RADIO APPARATUS Filed NOV. 29, 1946 6 Sheets-Sheet 4 ATTORNEY Nov. 13, 1951 Filed Nov. 29, 1946 w. D. LA RUE 2,574,604

AUTOMATIC SELECTOR MECHANISM FOR RADIQ APPARATUS 6Sheets Sheet 5 6'0 (/16. 9) .9 mm) m Zinnentor Gttomeg W. D. LA RUE Nov. 13, 1951 AUTOMATIC SELECTOR MECHANISM FOR RADIO APPARATUS 6 Sheets-Sheet 6 Filed NOV. 29, 1946 Imnentor m- QNN Sw LE K mum a La Rue Gttorneg Patented Nov. 13, 1951 UNITED STATES PATENT OFF ICE AUTOMATIC SELECTOR MECHANISM FOR RADIO APPARATUS William La Rue, Beach Haven, N- L, assignor to io Corporatio of Ame ca. a corporati n.

2!: D awa Application November 29, 1946, Serial'No. 713 005 adjustment of variable elements of radioapparaus su as a s tte s. and. rec i s to p et m e se r ted=19osit ns-v It is desirable-in certain radio. installations to e e u t ent of both receiver nd a smit e xp d t sl nd; accu atel t m one predetermined channel freq-uency. to another. Each di-ustment. of uch q pmen ordi i y involvesfthe angular positioning of a crummy. of

rotary tuning'condensers, or other variabletunin elements. and in-some, instancesalso a crystal torswi ch hepreseat inventio s i ct to an. automatic selector mechanismlor such use .in radio installations.

One of the objectso'fmy invention is to provide an automatic. selector mechanism of relatively s m e, a d-rugge const uc ion an sm i e,

low w h and h s-h. o dis on- A further. objector theinvention is to, provide positive locking means for theposition-determining elements. of the selector to thereby. withstand acc n alc nee o d u tm n oi the cbntrolled device which may result from vibration or other cause.

A still further object of the invention is toprovide a selector mechanism of such construction that it lends. itseli very; readily to control and a ju tm nt by a r at ve s mo electrica C011- trol system and which requiresbut-a short time, not exceeding 5, seconds, within which to complete a cycle of er tion A. lfurt er ion of autom tic clutch rele e. wh r by all drag is eliminated during the manual 's'et up of t e me hani m t de ired, pred term ned posit ns oi adiustme and whereby manua s t-up is permitted in either clockwise or counter-cloclp:

Wise direction Wit o t s te-st n t ac ur cy of the set-up.

A st f rther ob ect to pro ide n im r v lock. betw en he 'stomarm and he. sel tor discass y in Orde o reduc min mum he po sibility of disturbing he se ecto disc s ting du i e cki op r on- A more specific object of the invention is to pr vi e. a selecto m chan sm ora t c llyad u of predetermined angular positions, the combint n f a fram work in hi h the c n Shaft to. be adjusted in "ournalled, a selector disc-assembly havin ndividua ly at a stahle d sc mounted on said shaft, 9. multiposition rotatable Ject of the invention is. 'theprovis- 1 5 he. a control sha t. to one o ap u r dividuallyoperable in dependence upon the. drum position, pivotally supported from the framework and disposed externally of the drum, a reversible motor, means including a clutch interposed between said motor and control shaft operative upon rotationvof the. motor in one direction to drive the drum to a selected one. of its positions, and means including said clutch operative upon rotation of the motor in the. opposite direction to, drive the; selector disc-assembly to a position whereat-it is. stopped by the then operable disc o pin m an To the "accomplishment of the foregoing and such other oloiects and advantages as, may hereinarter appear, the invention further consists in the structural combinations hereinafter sought to he defined in the claims and described more in ds a li e. renewin specification d in on- J a tio it th acc m anyin d win s in invention Fig. 2' is a transverse cross-sectional view of the mechanism,tal en on the line 22 of Figs. 2, looking iii the'direction oi thearrows;

Fig.2 a is a detail view of a portion shown in Fig. 2;

Fig. 3 is a front elevational View of the selector mechanism shown in Fig. 1; Fig. 4; is a cross sectional View, taken on the line 5- -4 of Fig. 2, looking in the direction of the arrows, showing a selector disc held in locked position by its associated s'topsarm; Fig. 5 is a cross-sectional View, taken on the i e.5-5 I. ij 2. oo i th di e i n o th arr ws showin the c o e ve r l ion betwee the li -cam. and the dr dur n t early ar 9i ycle o operati n wh n h drum s ei drive a rede ermined p i i n;

Fig. Gis a cross-sectional view, similar to Fig. 5, showing the sliprcam actuated in the opposite direction for the purpose of backing up the drum to its "arnjiwloclging position shown in Fig. 4;

Fig. '1 is a cross-section taken on the line i-f'l of Fig, 2 looking in the direction of the arrows;

,li'ig. 8 is a crossssection taken on the line 87-8 Qf F Fig. 9. is. a schematic diagram of the electrical contro stem or o ati e cto m hanism; and

the cooperative relation between a stop-arm, a selector disc and the selector drum, which will be used in conjunction with the electrical system of Fig. 9 to explain a complete cycle of operation of the selector mechanism.

Referring now to the drawings, and more particularly to Figs. 1 to 4, the selector mechanism is shown to comprise a framework consisting of a front plate I and a rear plate 2 which are held in spaced, parallel relation by four-cross-rods 3 to 6, one in each corner, the front and rear plates being substantially rectangular in shape, as shown in Figs. 3 and 4, respectively. Bolts 1, one in each corner of the front and rear plates, serve to unite the cross-rods and plates together in a rigid framework. In order that the selector unit may be suitably mounted, the bolts at the rear plate are provided with threaded extensions 8 which are adapted to pass through apertures 9 in a supporting member l0, which may be the front panel of a receiver or transmitter, the unit being held in position by a nut II on each bolt extens on.

Centrallv arranged wit in the framework and extending through the front and rear plates is a control shaft |2 which is journalled in a ball bearing l3 retained within the front plate and in a ball bearing I4 retained within the rear plate. The forwardl extendin portion l5 of the shaft is externally threaded at l5 and is adapted to receive a manual control knob I6. W thin rear plate 2 is screw-threaded a plug M which serves to retain the ball bearing H! in position and also to adjust the clutch torque to be described later. The rearwardly extending portion l8 of the shaft is adapted to be mechanically coupled in a suitable manner to a device to be adjusted. s own as a variable tuning condenser I8 by wav of exam ple. In the disclosed embodiment of the present invention condenser !8' is of the type having semi-circular fixed and rotor plates. The rotor, however. being mechanically coupled to the control shaft, is also continuously rotatable, although the condenser is effective through only 180.

Carried by an intermediate portion IQ of the shaft l2, at the forward end thereof and between the end plates, is a selector disc-assembly shown generally at 20, and the p rts as ociated therewith are shown in cross-section in Fig. 2 to which reference will now be made. Just behind the front plate I, the intermediate portion I9 of the control shaft is provided with a portion 2| of enlarged diameter forming a shoulder 22 next adjacent shaft portion l9. Between said shoulder and a nut 23 which is screw-threaded on the shaft at 23' are disposed alternate spacers 24 and ring bushings 25. The nut 23 when tightened serves to clamp the several ring bushings and spacers against the shoulder 22 so that they rotate with the shaft as a unit. Encircling each of the bushings and disposed between adjacent spacers is a selector disc or ring 26 which is provided at one point in its periphery with a notch 21, shown more clearly in Fig. 4, there being a total of ten such selector discs in the device herein described. The discs or rings 26 serve as, position-determining members for the control shaft and are capable of individual adjustment around the ring bushings 25 in a manner later to be described, in order that the notches 21 may be disposed in various angular positions with respect to the control shaft, the adjusted angular positions of the disc notches corresponding each to one of the predetermined angular adjustmen ten in the present instance, of the device to be adjusted, such as the condenser [8.

For the purpose of clamping together the several selector discs 26 for rotation with control shaft 12 there is provided a pressure plate 28 slidably mounted on the enlarged shaft portion 2| so that by applying pressure to the plate in a rearward direction by means later to be described, the several discs are clamped together at their rims between a rearwardly extending rim portion 29 of the pressure plate and a second plate 30 formed integrally with the lock nut 23. The latter is provided with another integral portion 25' to serve as the bushing or hub for the rearmost selector ring 26. In order that pressure may be removed from the stack of selector discs to permit of individual angular adjustment thereof, and also for applying pressure to the discs to condition the assembly for normal operation, the shaft portion 2| is provided with a diametric bore or slot 3| which is elongated somewhat in the axial direction of the shaft (see Fig. 2a). A bar 32 is adapted to extend through the slot 3| and to have its opposite protruding ends seated within a pair of grooves or pockets 33 formed on the front face of the pressure plate. The pressure plate is thereby keyed to rotate with the shaft, but by reason of the axial direction of the slot the pressure plate is capable also of axial movement on shaft portion 2| in a manner later to be explained.

The front end l5 of the control shaft is provided with a central bore 34 within which there is fitted for sliding movement a sleeve 35, a nut 36 and a cap 31, all disposed end to end, the nut and cap being screw-threaded on the end of a rod 38 which extends through the sleeve 35 and also through a central aperture 39 in the rod 32. The rear end of sleeve 35 is adapted to abut against pressure-plate rod 32 and the front end of cap 31 is adapted to extend slightly beyond shaft end IS. on this end of the shaft, within the hollow of manual control knob I6, there is screwthreaded a plate 40 capable of being locked in position by a pair of screws 4| bearing against the inner wall of the knob. Plate 49 is provided with a pair of ears 42 between which there is supported a cross-pin 43 and on the latter there is pivoted a cam-lever 44. The pin is off-center with respect to the hub 45 of the lever to provide a cam surface at 46 for effecting the necessary sliding movement for the sleeve, nut and cap assembly 35-31. In Fig. 2, lever M is shown in its operative or locked position, with the sleeve 35 pushed rearwardly to exert pressure on plate 23 through rod 32. This is the normal operating condition for the disc stack of the selector assembly. However, by rocking lever 44 in the clockwise direction, as viewed in Fig. 2, the high side 46 of the cam is withdrawn from the forward end of cap 31, causing the pressure exerted by plate 28 to be removed since the assembly 35-31 is now free to move in a forward direction (to the right in Fig. 2). In this released position of lever 43 the disc assembly is conditioned for individual adjustment of the several selector discs. The manner in which such adjustment is carried out will be explained later. Cam surface 46 is in the form of an involute so that in returning lever 4 1 from released to locked position pressure on the disc stack will be applied gradually and uniformly.

In concentric relation with respect to the selector disc-assembly 2E] and suitably spaced therefrom is a drum 52, to the rear rim portion 53 of which there is attached in a suitable manvided; for that: purpose.

there are selector: discs.-

here gear 5'42: adapted? tm-rQtatELOm17118100111129 intervals, in the present case; assuming insefiect aspiral'formation:

Disposed externally of the discassembly 28 and? pivotally mountedon the cross -rod t (see Fig. 1) are apluralityct stop-arms or pawl's 66 (ten in the present-instance) which extend in a transverse direction to the axis: of thefcontro-l shaft: The stop-arms are retained in position by a: pair ofcnd collars t l, lil suitably' fastened to the rod and interposed between adjacent arms are spacingrings 62in order that the several stop-arms may be radiallyaligned with their respective drum slots which in turn are radially aligned with their respective selector discs;

Each stop-arm or pawl- Ell (Figs. 3 and a) is provided atone end with a locking part63 which at" the proper time during the-cycle of operation of the mechanism is-adaptedto drop through its corresponding drum slot 58 and then interlock with the disc notch 21 of the corresponding sel'eetordisc. At the other end the arm isprovided with a. hooked ortail part fi' lwhich coacts with the free end of'a leaf spring 65. The opposite ends of the spring are Suitably fastened to a member it carried On the cross-rod which: is

directly underneath the cross-rod: 33 which carries the stop arms. In a practical-r embodiment the springs 55 constitutedv the time of a comblike structure; the base of which, was:bo1t.e.d to one face of the member 66 which.v was a sleeve, square-shaped incross-section, and; suitably supported on the. cross-rod. Springs 65*. coact with the tail parts Mr ofthestop-arms in such manner that, in addition to their'normal functiorrv of. forcing the locking ends 5.3. into engage mentwith the selector discs 26, theyactto. take up. any play that may develop due to. wear, be.- tween. the arms 6i? and the rod,3.in the direction of, the. arrow 61 so that errors inthe finaladinstment, of the mechanism which, would otherwise arise are obviated thereby,

Drum 52 is capable of adjustment to any one of ten positions which correspond each to one of the, predetermined angular adjustments previously mentioned, and each of. said. drum positions determines the particular stop-arm which is to be effective at a given time. The drum, in being driven to each of said positions, is capable of continuous: rotation inonly one direction, which in the disclosed embodiment is in the clockwise direction when viewed from the front of the mechanism. This direction is indicated in l, 3 and t by an arrow designated R38 The drum actuating means will now be de scribed, with reference particularly to Figs. 2, 5 and 6. A slip-cam 1o havingthe configuration shown in Fig. 5 is pivoted at an intermediate point at H to the rear face of" drum gear 5s. The cam is provided with a central: aperture; 12

which encircles a; hub t3; extending rearwardh froma hedrumigear; In prdento; permit move: ment M the amyaboutitsppivot H. in a trans: verse.- di1f8017i01'17 th8 1 central: aperture; 12; otthe cam is elongated? as shown; The, slip-cam nor: mally is; in the position shown inpFig. 5 being urged to; that positionby means of a coil spring Mrhavingone end anchored, tothe cam at; 1.5 andwits-otherrend, anchored to the-drum gear at 135. Since. Rig. 5; is a viewloolringfrom; the rear, which. is oppositewto the direction from which Figs: 3 .andj lg areaviewcd, the counterclockwise direction of rotationgof; drum gear-5d andslip camfllizshcvmby the arrow-imFig. 5: corresponds tothe clockwise direction of rotation in. Figs, 3. and 4. of; the: same elements. The arrow in Fig. 5, therefore, has been designated by: the same reference character 68-.

Flor-the presentdt issuificient; to state thatthe motiveupowerior operating the selector mecha: nism is derivedv from an electrical, reversible motor which is coupled, through'suitable redllfir tion. gearing to. aclutch which in turndrives the slip-cam and drumassembly through alostrmQr tion connection, all to be described more; fully hereinafter; At H, in Fig-., 5. and also in Fig. 1, is shown astud which actually. is carried by an element of the above-mentioned lostrmotion connection; but for, the-present, inorderto ex plain the; coaction between the slip-cam and the drum, stud 112 may be. considered asbeing driven first in the direction of arrow '58, in Fig. 5 and then in thereverse direction indicated by arrow 19 in Fig. 6. 4

Assuming. then that the direction of motor operation is such thatstud H1 moves in theidi rection of: arrow. T85, the drum and slip-cam as.- seinblyreinain stationary until the stud reaches the right-hand edge 85* of cam projection 32, which is the position shown in Fig. 5. Continued actuation of the stud, however, causes the application of a. driving force to the cam at 88., and sincethe hub it" of the drum gear is now located at the bottom of aperture 12, the driving force is also applied to the drum gear, and the two will be rotated? together in the direction of arrow fiil to'a point determined by the electrical control system to be described later. Fig. 5 may be assumed to be one of the positions to which the drum gear may be actuated. in the manner described above. At this point the motor-reverses its direction of operation. The action that follows will now be described in connection with Fig. 6.

In the reverse direction of motor operation, stud 11- also rotates in the reverse direction (arrow 19 away from edge of cam projection 81. During the interval that stud M travels from its position shown in Fig. 5 to the dotted line position shown in Fig. 6, the drum gear re.- mains stationary. Upon continued rotation in the direction of arrow 153', the stud; Ti engages successively edges. 32 and 83' of thecam projection and rocks the slip-cam about its pivot H in the direction of arrow 84, depressing the cam until the upper edge of aperture it. rests on hub 7'3. This is the. position shown in Fig; 6. Stud 11' continues to ride on edge 83" in the direction of 'arrow- 1B, but before itreaches the right-hand edge 86 of" the cam projection, thev slip-cam 111, through the spring 75, will cause slight movement of drum. gear 5 3" and drum, 52 in the direc; tion-of arrow; 85; (Fig. 6). Movement of stud l-i continues,v however; and when it reaches the right-hand ed e 8.0.1. he. cam: I'll. is ised; y spring: 14. and the slip-cam anddrum. sc r a ain ring.

. bearings 97 and 55.

assume their normal relative positions with respect to each other, as shown in Fig. 5. The rotation of the drum and its gear in the direction of arrow 85 (Fig. 6), it will be noted, is in a direction opposite to that (arrow 68) in which the drum is normally rotated. The extent of this backward movement of the drum, although slight, is sufficient to lock an operative stoparm 60, and incidentally its associated selector disc, in a positive manner as will be explained later. This locking feature, it should be understood, is extremely advantageous in installations where excessive vibration is apt to cause an operative stop-arm to drop out or become disengaged from the notch 21 of its associated selector disc.

The clutch and lost-motion connection, mentioned above, which impart the necessary driving action from the motor to the selector mechanism, are disclosed in Figs. 2, '7 and 8. The clutch (Fig. 2) consists of a friction plate or disc $6 which encircles the selector shaft and is keyed thereto by means of a key or pin 8'! extending diametrically through a slightly elongated hole 88 in the control shaft to permit axial movement of the clutch plate. Since the shaft and clutch plate are thus keyed together, the shaft will be rotated (if free to rotate) whenever the clutch plate is caused to be rotated; and the clutch plate, on the other hand, will be stationary whenever the shaft is locked in position, that is, when actuated to one of its predetermined selected positions.

The clutch plate 86 is enclosed in a cupshaped retainer 89 located just in front of the rear frame plate 2. The retainer is provided with a central aperture 9!; through which the control shaft extends, and also with three equidistantly spaced apertured ears 95 (only one being shown in Fig. 2) whereat the retainer is attached by means of screws 532 to the rear face of a gear wheel 93. Interposed between the retainer wall 94 and the clutch plate 86 is a second clutch plate or ring 95 of oilite. Gear wheel 93 is the drive gear for the mechanism and is motor-driven through suitable reduction gearing, not shown. This gear is mounted on an annular hub member 96 within which there is retained a ball-bearing El! similar to the other ball-bearings I3, I4 and 55.

The lost-motion connection mentioned above is constituted by a ring member I which fits within an annular channel or groove formed by the rear face of gear 93 and a flange I0! formed on hub 96, said ring resting on a shoulder I02 of the hub which acts as a bearing surface for the A pin N33 is riveted to gear 93 at one point adjacent its periphery and extends into an open arcuate slot m4 (Fig. 7) of suitable length formed in the ring member. At a point diametrically opposite the slot, the ring member has riveted to it the stud 71, previously referred to in connection with Figs. and 6. The stud extends in a forward direction and is adapted to ride on the peripheral edge of the slip-cam I0 as previously explained and to cause rotation of the multi-position drum 52. In order to maintain the proper clearance between the drive gear and drum gear assemblies, a coil spring 98 of a few turns is interposed between their respective In operation, upon rotation of the gear wheel 93 in either direction, depending upon the portion of the cycle during which the motor is then operating, motion will not be transmitted to ring member I00 until pin I03 8 first reaches and then coacts with one or the other of the sides I05, I06 which define the opposite ends of the ring slot. The purpose of this lost-motion connection will be explained hereinafter in connection with the operation of the system as a whole.

The electrical control system for operating the selector mechanism above described in proper sequence is shown schematically in Fig. 9 and comprises a reversible driving motor I91, a 3-pole double-throw relay I 03, a remote control channelselector switch I09, a homing switch Ill], and a limit-and-holding switch III. Through a suitable gear train including reduction gearing, represented in the drawing by the dash line 101', the reversible motor I0! is adapted to drive gear 93 of the selector unit in either direction. As described in connection with Figs. 5 and 6, gear 93 is adapted to drive drum gear 55 in only the clockwise direction by way of stud T! and slipcam 10, and through suitable gearing represented by the dash line H2, drum gear 54 is adapted to drive the rotor H3 of the homing switch III]. This switch is provided with ten equi-angularly spaced contact brushes marked 1 to 10 to correspond to the number of predetermined positions to which the selector unit is settable. The rotor is conductive except for an insulating or cut-out portion H3. The gearing between drum gear 54 (or selector drum 52) and the homing-switch rotor I63 is such that they are phased to rotate in synchronism; that is, as cut-out H3 is successively moved from one brush contact to another, selector drum 52 is correspondingly rotated, and for each setting of the homing switch rotor there is a corresponding setting for the drum at which a drum slot 53 assumes a position directly underneath its corresponding stop-arm 60 to permit its locking part 63 to extend therethrough.

Channel-selector switch IE9, which may be located at a remote point, though not necessarily, is also provided with ten brush contacts, numbered 1 to 10, corresponding ones of which are connected to the homing-switch contacts by means of a 10-conductor cable H4. A rotary arm H5 is manually settable and is adapted to make selective contact with the contacts of the selector switch.

Relay I08 consists of a winding IE5 and three poles or armatures designated Iii, H8, and H9 With which are associated front contacts I, 3 and 5 and back contacts 2, i and 5. Pole I I1 is connected to the side of a voltage source (here designated 28 v.) and to ground E28 and is adapted to operate between front contact I and rear contact 2. Pole H8 is connected to the side of the voltage source and is adapted to operate between front contact 3 and back contact Pole H5 is connected to terminal A of motor It? and is adapted to operate between front contact 5 and back contact 5. The other terminal B of the motor is connected jointly to pole contacts 2 and 3. The motor field I2! is connected between pole H8 (or the side of the voltage source) and ground. The relay winding H8 also has one end connected to pole H8 (or the side of the voltage source) and its other end is connected by way of a conductor I22 to rotary arm IE5 of the manual selector switch.

Th limit-and-holding switch Iii is provided with an arm I23 which is adapted to be actuated between 'two limiting positions from the selector motor 9 drivegear 93through a diagrammatically at .I 25,. said friction driveenabling the switch :armsto idleat each limit of its travel. Associated with the switch-arm:I 23

are two. pairs of normally closed switch contacts I.26I2'I. and I28--I 29, the-former :pair serving as the .limit switch and the latter =.pair: as the holding-switch. "The contacts 2I =2B- and I28-of these switches are movable :and are: connected, respectively, by conductorstli30and I 3 I .to relay contact 6 and conductorLxIZL-"The switchacontacts I21 and I28 .are .fixed..and areconnected, respectively, by conductors .I32 .and meadweny contacted and-I.

A complete cycle of operation .ofstherselector mechanism will now be described. IIn EigB the electrical control systemzis shownzatxthe termination of :a previous cyclecof operation which, as. seen by the setting ofthe selector switch :arm I I5, is for an adjustedipcsitionloft'control shaft I2 (as Well .asof device 1:3 corresponding etc channel No. 1,..and in. .Fig.vlaiare wshownrthe operative position .of the selector ;.unit; elements whichwere efiective inlbringinglaboutisaid adjustment to the channel N0. zleshaft position. In this quiescent statesof the mechanism, xthe locking part 63.oftheNomlsstop-arm fifl isawedged into notch Z'Ivof the :No. 1-..se1ectorxdisc ifinand is retained thereinby reasomofthe forwardzedge acf the .No...1 drum"slot flarestingzonethe :upwardly. sloping zedge ib. of locking, part:i63. .-Also, due to the de-energized state ot the relaypthe poles I H to H9 :areqonltheir backucontacts, as shown in Fig. :9, .so :that.thgholdingmircuit for the .relay, namely, from il22, :'I:3I, 28,: I29, .133 to ground I20, is broken atipolel I'Land-its front contact I the motor circuit ifor operating the .in the "counter-clockwise directionti's broken at the-climitu-switch contacts ;I26,;I-l2-1 (this .being the-direction ofv thezmotor operation when relay poles ;I:I8.I.I9,are onltheiribackicontacts, the .position shown.;in Eig. 9):;,,:and .the motor .circuit for operating/the .zmotor tin the clockwise direction is broken at l the z frontcscontacts 3 .and (thiscbeingz theidirection;oftmotor operation when relay. :poles :I I8-- H19 ..are ionqtheir front contacts). The.;motor.'fieldrwinding [211, however, .remains zenergized ineeither;:positionzof the relay poles, vhavingla ,.direct-.connection between the side of :th'evoltage :source :and ground I20.

Let it. be .Lassumed Lnow, thatjit is ;desired .zto

adjust control shaft I 2= and-ivariable tuningacondenser iito-a: setting :corresponding :to channel No. 9. The selector switch arm II5 woulld gthen be rotated manuallyto :contact ,9. 'I-his,:completes a circuit from the .sjidenf :thel28 source, throughzwinding I16 ofthemelanacnnductor I22, switcharm. I Idon contactflrof selector switch oi E19, through thee-cable conductor'ltozcontact 9 of homing switchiliigrotor H3 vof;.said. switch, to ground-and'back to the-:,sideof-,:said source. As .aresult, the relay iswenergized-"to actuate polesI-I'I toI I9 to theirirespective...front contacts I, 3 and 5. :Withpoles I:I:8 .and;;.IrI.9 now closed on their respective gfrontcontacts t and 5, the motor terminals A-and Barerconnected respectively to the ,":a;1'l(1 -+i'SiClfiSOf'ifihGiVOlbQEG source, with the result that thevmotor isxenergize'd to rotate in the-clockwise direction. "withgpole I I! now onits frontcontact fI- the:holdingcircnit for relay windin II fi'is noweffectivegsaid circuit preventingpremature opening-of therelayacircuit at the cut-out I I3 ofthe homing:switchirotor I I3. Upon :energization ofrthezmotorndriveegear i friction drive-represented 10 93 of the'selector unitialso rotatesz-in-theclockwise direction, and the-movable arm iziiofaswitch II I is actuated from gear 1 93 :130 cause: theilimitswitch contacts I26I 2-'I:to close. This does not affect operation of the motor in thetclockwise direction since-the conductors I30 and r532 :are open-circuited at backrcontactsidand'd, it being remembered that' relay polesl I t9 andtiI id'arenow on their front contacts 55 .and S. Upon .the-..com-'- mencement of rotation of :drive :gear 93, the clutch retainervB I rotates .therewithiibnt normetion will be transmitted to :thecontrolshaft by reason .of :the locked engagement between the No. v1 stop-armfifiand the No.1 selector disk zii I 1 (Fig. 10a)- whichccauses the.clutch-s-95 to slip.

Thedrive gearcontinues to rotate, however, andidepending uponuthe. positioneofxpin I83 -in slot IIM, motion swill 'not be transmitted to the ringimember I011 zuntil sthe qain :coactsavith sl0t edge I96. When thislostemotion-is takenup, the pin I03 will commence rotating ringdiifl, and :the driving'stud '3'! carried thereby will alsotravel in the clockwise :direction (Rig t). In Fig. b t-he direction of :rotation .of drive pin H :is-in the direction of arrowi'l-a towards edgetfl-otth-e slip-ecam sIIl. Until stud Il reachesedge te drum 52 :remainsllocked :inthe position in which it =w-as set duringzthenprevious cycle, =that is;-in the No. l channel positionas shown in l ig. 10a. With driving stud."II now.inzcontactrwithledge- 86 (Fig. 5'),

rotationzof the z slipcarn:and: drum in'nthe clockwise. direction is begun. AItwill now be seen' from Fig. 101) thatasLthe 'drum is :rotated inethe clockwise direction theeleading edge a of the slot-58 backs 'awayfrom theainclined edge b o'f the stoparm thus .unlockingasaid arm. As the opposite edgec of theslot-coactsrwith edge'dof =the stoparm :it,;app1ies 1 aforce thereto sufficient to rock or cam the armupwardly about its pivot 3 and finally .to thus disengage the locking part F. 3 -from the discnotchilzsasshown inFig. l'Gc. 'Dueto action-ofrthe leaf 2 springififi, the stop-arm-thus disengaged is :caused to, ride on the outer surface on the .drum,;-Fig.1 10c. Since: the "disc assembly and control',shaft:;are .now free to rotate, they willibetrotatedxthroughLthefrictiOn :clu'tch in the sameidirection as .the drumand i drive gear.

:With 1 the i commencementlei -rotation of drum 52;:rotor I'.I3.:.o'f therhoming-switchis rotated-in synchronism.-therewith,. as:.previously explained, until cut-out. portion ,1 I3 arrives-opposite hrush contact Sxwhereat the-relaycircuit is momentarilyszbroken, but by reason of the normally-closed contacts. lit- 129 of switch ll I ,-the'- heretofore mentioned holding. circuit for the relay is closed to :thereby causelcontinued-motor operation in the clockwise direction. After the drive ge ar has revolved." about ':350 switch arm I I2 3 will have been :actuated :to one 'limitaof its travel wh'ereat contacts .I28'I129- are opened, thereby breaking the; holding .circuit for the relay winding. The friction drive :I 25:.then slips allowing the switch arm.to'.idle,=ats said position. -"1 he homing switch continues to lrevolveiuntilit opens the relay-circuit-,at;9 I I3; releasing the relay andcausing the mOtOIEZtOE operateiin thereverse or "counter-clockwise direction. "At the -termina'tion of the motor operationsin the: clockwise direction, the drum will ihaveg'been rotated to: a position corresponding toithat of the homingeswitch -rotor, so that the No. 9 drum slot 58 comes intomegistry-with the'rpart 63.of the No.-9:stop-arm. This isstxown in-Fig; IOd.

1 The-"second :half I of the cycle of operation-commenceszwith thee-motor operating in -the reverse or counter-clockwise direction which occurs, as mentioned above, when relay Hi8 has been deenergized and poles H! to H9 are returned to their back contacts I, 3 and 5. With pole H8 on front contact 3 the B terminal of the motor is connected to the side of the source, and with pole H9 on front contact 5 the A terminal of the motor is connected to the side of the source. These potentials being the reverse of what they were for the clockwise rotation of the motor, the motor will now be actuated in the counter-clockwise direction.

As explained in connection with Fig. 6, in the reverse direction of motor operation, the driving stud ll backs awayfrom the edge 88 of the slipcam and continues in the direction of arrow it toward edge 82 on the other side of cam projection 8!. Simultaneously the clutch is operative to drive control shaft 52 and disc-assembly 253 in the same or counter-clockwise direction until part 63 of the No. 9 stop-arm is forced by action of its spring 65 to drop into notch 21 in the No. 9 selector disc 26 (Fig. 10c), stopping further rotation of the discassembly, when the clutch will begin to slip as in the first half cycle. At this time edge a of the No. 9 drum slot 53 is spaced from the inclined edge I) of the No. 9 stop arm a distance of approximately of an inch. Shortly after the selector disc is locked in position, as mentioned above, the driving stud T. approaches the other side of cam projection 8i, and then rides up incline 82 and onto top edge 83 to bring about the slight backward travel of the drum, described above in connection with Fig. 6, to thereby lock the stop-arm securely in position as shown in Fig. 10 By this time switch arm l23 has been rotated in thecounter-clockwise direction to its other limiting position whereat it opens limit switch contacts E26, I21 thereby breaking the motor circuit and stopping operation of the motor. This completes the cycle of operation.

In order that the desired synchronism between the drum and the homing switch may be maintained in spite of the slight backward travel of the drum which is utilized to effect locking of an operative stop-arm, there is provided, between the rotor I I3 of the homing switch and its operating shaft, a lost-motion connection (not shown) which permits said shaft to rock through a corresponding angle in the reverse direction without disturbing the position of the rotor.

In some instances, it may be necessary to setup the selector so that the disc notches 21 of certain of the discs are spaced apart angularly only to a slight degree. This would arise where the operating channels of the equipment are closely spaced. In order to meet this contingency, there is provided the previously described lost-motion connection (pin I03 and slot I84) between the clutch and the driving stud. This connection permits the selector. disc-assembly to rotate in the reverse directionthrough a substantial part of a revolution, in addition to the excursion of stud 11 in rotating from engagement with the edge 80 of cam projection 8| into engagement'with the edges 82 and 83, thereby assuring that the notch 27 of the selector disc made operative by the position at which drum 52 is stopped by the homing switch, will be brought into engagement with its corresponding stop-arm 60 before the limit switch is opened.

The lost-motion connection H13, H14 between drive gear 93 and ring I00 also performs a useful function in the movement of stud 11 over the edge 83 of cam projection 8| (Fig. 6) to the right,

12 as seen in Fig. 5. As stud H passes on the right-' hand corner of the cam projection, spring 74 snaps slip-cam back to the position seen in Fig. 5. This produces a reaction between stud ill and slip-cam 10, which in the present structure merely throws the ring I00 and stud 11 in some degree clockwise on bearing I02. This produces substantially zeroreaction tending to move the drum 52. If stud 11 were fixedly connected to worm wheel 93, its movement off of the cam projection would create a relatively strong reaction in a direction tending to move drum 52 out of proper locking engagement with the part 63 of the stoparm, thereby also tending improperly to close the limit switch.

A multiplicity of selector units similar to that herein described may be utilized in a single installation, with the several units driven from the same motor. In one case, in a two-way communication system, six such units were employed, four in the transmitter and two in the receiver, with the several drive gears 93, one in each unit, driven from the motor through suitable gearing and counter-shafts. In Fig. 9 there is shown a second selector unit S similar to the one described above, with its drive gear 93 driven from the same motor I01. Since said drive gear 93 is driven in synchronism with the drive gear 93 of the first selector unit, it is unnecessary to associate a separate homing switch with its drum gear 54' or a separate limit switch with its drive gear 93. A

The procedure for initially setting up the several position-determining discs or rings 25 of the selector unit is as follows: The multi-position channel selector switch IE9 is first set to any desired position, such as, for example, channel po sition No. 1. This initiates operation of the mechanism, and upon completion of the cycle as above described, the selector disc corresponding to channel No. 1 will have been rotated to a position whereat it is locked by the corresponding No. 1 stop-arm. With the disc so locked, lever 44 at the front of the manual control knob is pulled out to thereby unclamp the disc stacks. The control knob is then manually rotated, the No. 1 disc still being locked, until the variable element is turned to its desired angular setting. The discs are then clamped together again by pushing in lever 44 to its first position. Thereafter, for the No. 1 position of the control switch, the selector disc-assembly will be actuated automatically to the position justset. The same procedure is followed for all of the other positions of the control switch.

By reason of the fact that the selector discs are mounted on the ring bushings 25 with sufficient friction and are unclamped at their peripheral rim portions which are separated by spacers or washers locked against rotation, the manual rotation, in the setting-up operation, of all of the discs of the stack, except the one that is held in locked position, will not cause accidental displacement of any of the other discs which may have been previously adjusted.

As a further precaution for preventing accidental rotation of the selector discs (other than the one in the process of being adjusted), means are provided to hold pressure plate 23 in its disc clamping position under spring action. This means comprises a coil spring MO (Fig. 2) which encircles the rod 38 within sleeve 35 and extends between the shoulder [4| within the sleeve at the left and the nut 36 at the right. Consequently, in the released position of lever 44, due to the expansion of spring i lid-cane!tis forcedragainst the cam surface of le.ver,44, and the leit, edge of sleeve 35 is forced against pressure plate rod v32. The forceeso applied -to the pressure plate is notias great as. that applied in. the locked position of lever 44 but it is suiiicientto prevent undesired disc rotation.

'.In the released position of. lever 44, when ,the selector discs. are being individually adjustable, it is most desirable to have friction clutch Mei-S inefiectiveto thereby remove the dragon the discassembly during the manual rotation thereof. Theconstruction for accomplishing this involves aplunger 142 (Fig. 2) fitted within acentral-bore l43'formed in the control shaft i2. .Thisibore communicates with theclutch pin slot .88.-at the left and with a secondbore [44 of enlargeddiameter at the right. The lunger at the right terminates in a heady I45 which is slidablyoretained within bore I44, and a coil spring. 146 which .tends to-urge the plunger to the right is interposed .between the headand a shoulder 41. :Acoilspring 148' is-retained within bore 144 betweenv plunger head I45 and a washer I49, and-the end of the rod 38-which extends through the pressure plate rod-abuts against the right faceeof the washer 449. It will be seen from this constructionthat,

during the setting-up process and-when the lever is released, nut 36 and cap 31will-move to the right somewhat'under action of spring Me, and with-it will move rod 38, allowing removal of pressure of the plunger l42on-the clutch-disc pin 81. This movement ofrod'38 is aided to some extent by expansion of the coil 148 which acts also to keep plunger I42 against the-c1utch pin 8]- but at a pressure less than that in the locked position of lever 44. The pressure isstill further reduced by action of the spring 146 which tends to move the plunger to the right. -Therefore, in the released position of lever-44, with thepressure on the clutch pin reduced to permit slippage between theclutch plates, it is possible by means of the manual control knob ieto rotate the control shaftand the disc-assembly freelyin eitherdirection without causing movement of the drive gear 93 (including the gear train-inrnesh therewith) and clutch retainer 94 carried thereby, which would otherwise act as excess loadif this precaution were not taken.

In order to adjust or regulate the clutch torque, after initial assembly of the mechanism or, when it is found necessary, after extended use ,due to wear of theclutch parts, the screwthreaded plug 14' at the rear of the unit is rotated asufiicient amount in one direction or, the other to' impart the necessary axial movement to the clutch retainer .94 through the medium of ball-bearing [4. As the result of this axial movement of theretainer more or less pressure is caused to be applied betweenclutchplatesdfi and 95 as well as between clutch plate"$5 .and the inner surface of the retainer. A set-screw M on the outer face -of the lug serves to lock the plug in its adjusted position.

A ia a j men .o th -13. by rotaiien p nu 36 an c n 3 threaded. o th nt en p th i qd. i u tose u a rope aneabetween pressure on the clutch along rod M2 and pressure on the selector discs through pressure plate 28. Such adjustment is necessary because of variations due to manufacturing tolerances.

While I have shown and described a preferred embodiment of my invention, it will be understood thet various modifications and changes will occur to those skilled in the art without departing from the spirit andscope-of thisinvention. if thereforecontemplate by the appended claims .to include any such modifications as fall within the true spirit and scopeof my invention.

:What I claim is:

.l. A motor-operated selectormechanism adaptedto. effect the automaticadjustment of a rotatable device to one .of a plurality of predeterminednangular positions, comprising a stack of position-determining rings, each corresponding to one of said positions, mechanically coupledas a unit to. the device to beadjusted, said rings being axially spaced on a shaft and individually angularlyadjustable thereon, a drum encircling said rings provided with a plurality of slotswhich are aligned each with one of said rings and which arealso equi-angularly spaced, said drum being selectively actuatable to settings-which correspond each to one of said predetermined positions, a plurality of stop-arms, one for each ring, disposed externally of the, drum and each having a locking'part which normally rests on the drum, saiddrum, depending upon the angular setting to which it is actuated, permitting a stop-arm looking part to drop through the drum slot aligned therewith and to coact with the aligned ring, said stop-arm eventually locking said ring to thereby stop said ring-stack and the device to be adjusted at the predetermined position corresponding to said drum setting, and drive means foractuating said drum and ring stack in a predetermined sequence of operations.

A motor-operated selector mechanism adapted to effect the automatic adjustment of a rotatable device to one of a plurality of predetermined angular positions, comprising a stack of positiondetermining rings, mechanically coupled as a unit to the device to be adjusted, said rings being axially spaced on a shaft and individually angularly adjustable thereon, a drum encircling said rings provided with a plurality of equi-angularly spaced slots, a plurality of stop-.armsdisposed ex.- ternally of the drum and each having a locking part which normally rests on the drum, said rings, drum slotsv and stop-arms being. arranged so that corresponding ones of eachare disposed in coplanar relation, each such set of coplanar elements corresponding to one of. said predeterminedan-gular positions of adjustment, said drum being selectively actuatable to setting which correspond each to one of said predetermined positions, said drum, depending upon the angular settingto which it is actuated, permitting the locking part of only one of the stop-arms to drop through its aligned drum slotand to coact with its. aligned ring, said stop arm eventually locking said ring to thereby stop said ring-stack and the device, to. be adjusted at the predetermined position corresponding to said drum setting, and drive means for actuating said drum and ringstack in a predetermined sequence of operations.

; 3. A- selector mechanism in accordance with the invention definedin claim 2 wherein the several-rings of the stack aredisposed between a lock-nut fastened to the shaft and an axially movable pressure plate, and means operableato apply pressure to said platein oppositiontoa spring whereby the several rings are clamped together to rotate with the shaft, said spring upon release of the pressure means tending to hold said rings together with sufficient force to permit of individual angular adjustment of the rings without disturbing the adjustments of the other rings of the stack.

4. A selector mechanism in accordance with the invention defined in claim 2 wherein the several rings of the stack are disposed between a lock-nut fastened to a shaft and an axially movable pressure plate, means coacting with the pressure plate adapted upon movement in one direction to force said plate to an operative position whereby the several rings are clamped together and upon movement in the opposite direction to permit said plate to move to an inoperative position whereat the several rings are unclamped, said plate-coacting means comprising a sleeve member Which abuts the pressure plate at one end and is provided with a cap at the other end and a coil spring between said sleeve and cap, the action of the spring being such that in the inoperative position of the coacting means the sleeve member is forced against the pressure plate with sufiicient force to permit of individual angular adjustment of the rings without disturbing the adjustments of the other rings of the stack.

5. A selector mechanism as defined in claim 2 including a friction clutch between the drive means and the ring stack, means for clamping together the several selector rings of the stack to operate as a unit and for unclamping said rings to permit individual angular adjustment thereof, and means under the control of said ring clamping means operative to make the clutch eifective when the rings are in the clamped condition and ineiiective when the rings are in the unclamped condition.

6. A selector mechanism adapted to effect the automatic adjustment of a device to one of a plurality of predetermined positions, comprising a selector disc assembly mechanically coupled to the device to be adjusted and having notches arranged therein, angular positioning means having apertures therein and being selectively actuatable to said apertures which constitute settings which correspond each to one of said predetermined positions, lever means arranged in cooperative relationship With the notches of said disc assembly and the apertures of said angular positioning means, said lever means being operable upon actuation of said angular positioning means to a selected one of its settings to stop the disc assembly at a position corresponding to said setting, clutch means for actuating said device and said selector disc assembly in a predetermined sequence of operations, clutch adjusting means for varying the clutch pressure to provide sufficient friction to drive the selector and said device, and drive means for driving the clutch means.

7. A selector mechanism adapted to effect the automatic adjustment of a device to one of a plurality of predetermined positions, comprising a selector disc assembly mechanically coupled to the device to be adjusted, said assembly having a plurality of discs each having a notch therein, a member encircling the disc assembly having apertures corresponding in number to the notches of said disc assembly and being selectively actuatable to settings which correspond each to one of said predetermined positions, lever means positioned in line with the notches of said disc assembly and the apertures of said encircling member means urging said lever means into engagement with said assembly and said member upon actuation of said member to a selected one of its settings to stop the disc assembly at a position corresponding to said setting, adjustable clutch means for actuating said device and said selector disc assembly in a predetermined sequence of operations, and drive means for driving the adjustable clutch means.

8. A selector mechanism adapted to effect the automatic adjustment of a device to one of a plurality of predetermined positions, comprising a selector disc assembly mechanically coupled to the device to be adjusted and having notches in each of the discs constituting said assembly, a member encircling the disc assembly and having apertures therein and being selectively actuatable to settings which correspond each to one of said predetermined positions and to one of said apertures, means individual to each of said settings resiliently urged into potential engagement with the notches of said disc assembly and the apertures of said encircling member operable, upon actuation of said member to a selected one of its settings, to stop the disc assembly at a position corresponding to said setting, and clutch means for actuating said device and said selector disc assembly in a predetermined sequence of operations, clutch adjusting means for varying the clutch pressure to provide sufiicient friction to drive the selector and said device, and drive means for driving the clutch means.

9. A motor-operated selector mechanism adapted to effect the automatic adjustment of a device to one of a plurality of predetermined positions, comprising a selector disc assembly mechanically coupled to the device to be adjusted and having notches therein, angular positioning means having apertures therein and being selectively actuatable to settings corresponding to said apertures and which also correspond each to one of said predetermined positions, a plurality of resiliently biased pawl members arranged for potential insertion into the notches of said disc assembly and the apertures of said angular positioning means, only one of said pawl members being operable upon actuation of said angular positioning means to a selected one of its settings to stop the disc assembly at a position corresponding to said setting, clutch means for actuating the selector and said device, drive means for driving said clutch means, manually operable means also for adjusting said device, and clutch releasing means to make operable the ease of manipulation of the manually operable means.

WILLIAM D. LA RUE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,174,552 Collins Oct. 3, 1939 2,391,470 May Dec. 25, 1945 2,512,664 May June 27, 1950 

